Investors are encouraged after President Barack Obama and congressional leaders held talks Friday about ways to avoid tax increases and mandatory government spending cuts set to take effect Jan. 1. Without a compromise, some economists believe the U.S. could eventually drop into a recession.

Separately, the Greek government has presented emergency legislation aimed at landing its next bailout payment.

Commodities also are benefiting from a weaker dollar. Because commodities are priced in dollars, a weaker dollar makes them cheaper for traders who use other currencies.